Message-ID: <971536df1001180747v2b5b87bufc4da3e2110c5307@mail.gmail.com>
Date: 2010-01-18T15:47:53Z
From: Gabor Grothendieck
Subject: column selection for aggregate()
In-Reply-To: <4B547604.8060600@uni-hamburg.de>
Try summaryBy in the doBy package. e.g. using the built-in CO2
summarize each numeric variable by each factor except for the factors
Plant and Type:
library(doBy)
summaryBy(. ~ ., data = subset(CO2, select = - c(Plant, Type)))
On Mon, Jan 18, 2010 at 9:53 AM, Ivan Calandra
<ivan.calandra at uni-hamburg.de> wrote:
> Hi everybody!
>
> I'm working on R today so I have a lot of questions (you may have
> noticed that it's the 3rd email today). I'm new on R, so please excuse
> the "spam"!
>
> I have a dataset "ssfa" with many rows and the column names are:
> ?> names(ssfa)
> ?[1] "SPECSHOR" ?"BONE" ? ? ?"TO_POS" ? ?"MEASUREM" ?"FACETTE" ? "SHEARFAC"
> ?[7] "ENA_BA" ? ?"SEL_FACET" "SEL_MEAS" ?"Asfc" ? ? ?"Smc" ? ? ? "epLsar"
> [13] "HAsfc4" ? ?"HAsfc9" ? ?"HAsfc16" ? "HAsfc25" ? "HAsfc36" ? "HAsfc49"
> [19] "HAsfc64" ? "HAsfc81" ? "HAsfc100" ?"HAsfc121" ?"Tfv" ? ? ? "Ftfv"
>
> I want to aggregate that way:
> ssfamean <- aggregate(ssfa[c("Asfc", "Smc", "epLsar", "HAsfc4",
> "HAsfc9", "HAsfc16", "HAsfc25", "HAsfc36", "HAsfc49", "HAsfc64",
> "HAsfc81", "HAsfc100", "HAsfc121", "Tfv", "Ftfv")], ssfa[c("SPECSHOR",
> "BONE", "TO_POS", "FACETTE", "SHEARFAC", "ENA_BA")], mean).
>
> As you can see, it is very long since I have many variables. Basically I
> want to select all numerical variables (10 to 24), and all categorical
> variables except MEASUREM, SEL_FACET and SEL_MEAS without having to
> write each of them. I would also like to avoid writing the names, the
> indexes would be nice.
> I tried with:
> ?> ssfamean <- aggregate(ssfa[c(ssfa[[10]]:ssfa[[24]])],
> ssfa[c("SPECSHOR", "BONE", "TO_POS", "FACETTE", "SHEARFAC", "ENA_BA")],
> mean)
> but it obviously doesn't work (well "obviously"...)
>
> Could anyone help me on this?
> Thanks in advance
> Ivan
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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